1. Field of the Invention
This invention relates to a hydraulic tail trailer including a front axle supported on a front suspension system and a rear axle supported on a fixed rear suspension system and more particularly to a hydraulic tail trailer wherein the main tail thereof is hingedly connected to the trailer frame forward of the centerline of the rear axle. Even more particularly, this invention relates to a hydraulic tail trailer wherein the front axle thereof is selectively longitudinally movable to multiple positions with respect to the fixed rear axle to enable the trailer to carry additional weight as the spacing of the front axle with respect to the rear axle is increased.
2. Description of the Related Art
The trailer transportation of heavy or large farm and industrial equipment requires special loading ramps at the rear end of the trailer. A typical hydraulic tail trailer of the prior art includes a rear axle supported on a rear suspension system and a front axle supported on a front suspension system. The rear axle and rear suspension system is sometimes referred to as a rear running gear assembly. The front axle and front suspension system is sometimes referred to as a front running gear assembly. In most prior art trailers, the rear and front suspension systems are longitudinally fixed to the trailer frame such as shown in U.S. Pat. No. 7,547,178 which is owned by the assignee of the instant invention. In some cases, both the rear and front suspension systems are slidably mounted, as a unit, on the trailer frame such as shown in U.S. Pat. No. 5,013,056. In other prior art trailers, the rear axle may be moved forwardly on the trailer frame for unloading and loading purposes only such as disclosed in U.S. Pat. No. 5,215,426 which is also owned by the assignee of the instant invention.
In U.S. Pat. No. 7,547,178, the location of the hinge between the main deck and the main tail assembly is located forwardly of the centerline of the rear axle to provide a main tail having an increased length thereby providing a lower loading and unloading angle without increasing the overall length of the trailer. However, in U.S. Pat. No. 7,547,178, the spacing of the rear and front axles is fixed. Thus, the weight which may be legally carried by the trailer of U.S. Pat. No. 7,547,178 is fixed and cannot be increased since axle spacing determines the weight which may be legally carried by a trailer.